Ionomer modified polypropylene compound for superior scratch performance,low blushing and molded in color with controllable gloss

ABSTRACT

The invention pertains to a polyolefin blend, which imparts superior physical properties, which may include enhanced scratch resistance, toughness and low temperature performance, and higher flexural modulus and rigidity. The blends in this invention impart improved performance and processability over existing products.

OBJECTS OF THE INVENTION

The development of a compound comprised of a polypropylene, an impactmodifier functionalized and/or crosslinked, and/or ionomer wax orfunctionalized monomer, and an ethylene-based polyolefin-metal salt. Thepolypropylene may be homopolymer, a copolymer of propylene and ethylene,and an oxy-propylene or a blend thereof. The impact modifiers andfunctionalized modifiers may include a copolymer of ethylene and analpha-olefin modified with maleic anhydride; a styrenic copolymer orelastomer with maleic anhydride grafting; ethylene vinyl acetatemodified with maleic anhydride or hydroxyl ethyl acrylate; terpolymersor copolymers of ethylene, butyl acrylate, and or glycidyl methacrylate;terpolymers of ethylene, ethyl, methyl or butyl acrylate, and or maleicanhydride. The ionomer portion may be a copolymer or terpolymer modifiedwith acrylate. The methods to produce such blends, as well as, theproperties of said blends will be discussed. It will be shown that saidblends have certain advantages over other prior arts.

SUMMARY OF THE INVENTION

What we therefore believe to be comprised by our invention may besummarized inter alia in the following words:

A polyolefin blend comprising a propylene containing polymer,

an ethylene copolymer elastomer, which is a reaction product of acopolymer of ethylene and at least one alpha-olefin, this elastomerfunctionalized with maleic anhydride,

wherein the alpha-olefin is selected from 1-octene, 1-hexene, 1-heptene,1-butene, 4-methyl-1-pentene, and mixtures thereof, and

an ethylene-based polyolefin-metal salt which is the product of anethylene acid copolymer and a metal salt, the polyolefin-metal saltbeing an ionomer, an alpha, beta ethylenically unsaturated carboxylicacid polymer in which the acid units are neutralized with metal ion (s).

The polyolefin blend wherein the propylene polymer may be at least oneof a homopolymer propylene or a random or block copolymer of propyleneand ethylene, and the polyolefin blend maybe from about 10 to 80 weightpercent of the propylene polymer, from about 1 to 50 weight percent ofthe ethylene copolymer, and from about 5 to 60 weight percent of thepolyolefin-metal salt.

The polyolefin blend wherein the propylene polymer, for optimal hardnessand scratch resistance, consists essentially of from 40 to 75 weightpercent of the propylene polymer; from about 1 to 25 weight percent ofthe ethylene copolymer; and from 5 to 35 weight percent of thepolyolefin-metal salt of the blend.

The polyolefin blend wherein the ethylene copolymer is crosslinked withperoxide or silane with a catalyst selected from the transition metalsof Group VIII, including complexes of these metals, this materialoptionally crosslinked prior to compounding or in situ.

The polyolefin blend wherein the ethylene copolymer is acrosslinked/partially vulcanized thermoplastic elastomer.

The polyolefin blend wherein the propylene polymer is selected from atleast one of a homopolymer propylene, a random or block copolymer ofpropylene, and ethylene, and the polyolefin blend may be from about 5 to75 weight percent of the propylene polymer, from about 1 to 50 weightpercent of the ethylene copolymer, and from about 5 to 65 weight percentof the polyolefin-metal salt.

The polyolefin blend which includes an interfacial impact modifierselected from a styrene-ethylene interpolymer, styrenic block copolymeror elastomer, and a random styrenic copolymer or elastomer, all of whichmay have been modified with maleic anhydride.

The polyolefin blend wherein the styrenic copolymers, interpolymers orelastomers modified with maleic anhydride represent between 1 to about30 weight percent of the blend.

The polyolefin blend further comprising an ethylene vinyl acetate (EVA)with a vinyl acetate level between 5 to 80 weight percent with maleicanhydride or hydroxy ethyl acrylate.

The polyolefin blend wherein the functionalized ethylene vinyl acetaterepresents between 1 to 30 weight percent of the blend.

The polyolefin blend further comprising one or more of terpolymers orcopolymers of ethylene, butyl acrylate, and glycidyl methacrylate (GMA);terpolymers of ethylene, ethyl, methyl or butyl acrylate, and maleicanhydride (MAH); terpolymers of ethylene, acrylic ester and maleicanhyrdride.

The polyolefin blend wherein the MAH (unsaturated anhydride) andacrylate (GMA) may be physically crosslinked prior to addition to blendor in situ.

The polyolefin blend wherein the modified acrylate copolymers orterpolymers may react with the free acid of the ionomer component.

The polyolefin blend wherein the modified acrylate copolymer orterpolymers represent between 1 to 30 weight percent.

The polyolefin blend wherein the polyolefin-metal salt is a copolymer orterpolymer ionomer, which is partially neutralized with a metal saltfrom 5 to 95%.

The polyolefin blend wherein the terpolymer ionomer is modified withmethyl, butyl, or ethyl acrylate; wherein the acrylate content from 1 to25 weight percent.

The polylefin blend wherein the acrylate content represents between 10and 25 weight percent.

The polyolefin blend wherein the metal ion is selected from the groupconsisting of lithium, sodium, potassium, magnesium, calcium, barium,lead, tin, zinc, aluminum, cadmium, and mixtures thereof.

The polyolefin blend wherein the ethylene copolymer may include a lowmolecular weight ionomer wax or functionalized monomer representing fromabout 1 to 20 weight percent.

The polyolefin blend further comprising a filler from about 1 to 40weight percent.

The polyolefin blend wherein the mineral filler is selected from talc,calcium carbonate, wollastonite, calcium sulfate, barium sulfate, metalfibers, nanocomposites, ceramic fibers and powders, polymeric fibers,crosslinked polymers, mica, silica, carbon fibers, metal fibers, clay,glass fibers, glass spheres, conductive fillers such as polyaniline, andsulfonated materials such as AMPS.

The polyolefin blend further comprising a surface and mold release agentsuch as high molecular weight silicone and silicone masterbatches, fattyacids (i.e. olyel palmitamide, erucamide and behanamide) representingfrom about 0.1 to 10 weight percent.

A process for preparing an article from a polyolefin blend consistingessentially of:

providing a propylene polymer containing polymer,

adding a compound which may act as an impact modifier or interfacialagent selected from at least one of: ionomer waxes or functionalizedmonomers; impact modifiers and functionalized modifiers; a styreniccopolymer or elastomer with maleic anhydride grafting; ethylene vinylacetate modified with maleic anhydride or hydroxyl ethyl acrylate;terpolymers or copolymers selected from one or more of ethylene, butylacrylate, and glycidyl methacrylate; terpolymers of ethylene, ethyl,methyl or butyl acrylate, and maleic anhydride; ethylene-propylenerubber with maleic anhydride grafting, the ionomer portion may be acopolymer or terpolymer modified with acrylate;

adding an ethylene based polyolefin-metal salt that is a reactionproduct of an ethylene containing polymer and a second organic monomercontaining a hydrophilic moiety; such component being at least partiallyneutralized with a metal salt between 5 to 95%;

mixing the ethylene copolymer until partially or completely crosslinkedand adding to the blend; or

crosslinking in situ while adding the propylene polymer andpolyolefin-metal salt; or

mixing the propylene polymer, ethylene copolymer, and polyolefin-metalsalt; and

injection molding, blow molding or extruding the blend into an articlewhich will display high scratch resistance, low blushing upon impact,low temperature requirements when mandated, tape adhesion, molded incolor, controlled gloss levels, superior weatherability, and sonicwelding capabilities.

FIELD OF INVENTION BACKGROUND OF THE INVENTION

Many have sought to develop an ionomer modified polypropylene compoundwith a complimentary blend of scratch resistance, processability,compatibility, toughness, ductility, and rigidity. These performancecriteria are particularly important within the automotive industry. Withthe advent of modified polypropylene blends with metallocene typepolymers and other rubbers, researchers have attempted to producecompounds with such performance characteristics, but failed. As may bereadily recognized, polypropylenes are appropriate for applicationswhich require high flexural modulus, must be environmentally friendlyand weatherable, as well as possessing recyclability, andprocessability. Moreover, higher crystalline, homopolymer polypropylenesmay exhibit good scratch and mar resistance, but lack the impacttoughness and in some cases low temperature properties mandated by therespective automotive application.

Compounding the issue is the necessity to control gloss and performagainst parts that are traditionally painted and in some cases have lowtemperature ductility. The addition of a rubber phase with a controlleddomain size will impart a lower gloss surface. These controlled rubberphases will impact the surface morphology desired. The rubber portionwill provide, in most cases, some low temperature ducility and even aidin tape adhesion to body side moldings. However, these modified blendslack the necessary scratch resistance of pure polypropylene compounds.

As the crystallinity of polypropylene increases, the surface hardnessincreases. With the addition of mineral filler, the surface hardnessappears to only improve nominally. Moreover, the physical blend appearsto deteriorate in terms of impact resistance, notch sensitivity, andwhitening around scratches and point of impact. The morphology of thefiller, the aspect ratio, as well as, the surface treatment seem tocontribute to stress whitening. Importantly, if the fillers do notuniformly ‘wet-out’ or begin to ‘debond,’ the area around theparticulate surface becomes exposed and thus contributes to the stresswhitening of the compound.

The chemistry of the ionomer, as well as, the thermally reversiblecrosslinking within this thermoplastic contribute significantly to themar resistance, a controllable gloss level, and some of the novel impactmodification not associated with traditional PP and TPO blends.Ionomers, which are traditionally, known for their clarity and highgloss, can be readily modified control the gloss. Moreover, whenincorporated in PP blends, ionomers will not dramatically deterioratethe overall cycle times and or mandate tooling changes.

In U.S. Pat. No. 6,403,721, it is suggested that the compatibilitybetween polyolefins, especially polypropylene, with ionomers of ethyleneand/or ethylene based polyolefin-metal salts, is greatly enhanced by thepresence of polypropylene based polyolefin-metal salts. It is suggestedthat the physical polymers of these heterogeneous blends are controlledby the interfacial interactions between the constituent phases. With thepresence of the propylene based polyolefin-metal salt, the dispersion isimproved and there is superior reinforcement. The ionic bonding betweenthe propylene-based polyolefin-metal salts in a propylene and theethylene-based polyolefin-metal salts contributes to the improvedscratch resistance, stiffness, and impact resistance.

Blends completed with a polypropylene polymer, propylene basedpolyolefin-metal salt in propylene and an ionomer did not showsufficient impact resistance at low temperatures, specifically −15 to−30 deg C. Using a multiaxial test, a critical test utilized by theautomotive industry almost exclusively, these blends showed some brittledeformation even at room temperature. The functionality in thesepropylene-based polyolefin metal salts is roughly 1 wt. %, moreover, thepropylene is traditionally homopolymer. This does not provide sufficientinterfacial interaction between the propylene and ionomer; with thissaid, the ionomer portion will not adequately perform as an impactmodifier.

DETAILED DESCRIPTION OF THE INVENTION

The present invention offers a polyolefin blend that will deliver lowtemperature impact performance, superior scratch resistance, goodelongation, high flexural modulus and rigidity, while meeting the hightemperature cycling requirements and processability.

This invention relates to the blends of a polypropylene (homopolymer orcopolymer of propylene and ethylene), a functionalized and orcrosslinked rubber/elastomer, and a partially neutralized ionomer (5 to95%). The term ionomer refers to a thermoplastic copolymer containingbetween 80-91 weight percent of alpha-olefin units and about 7-20 weightpercent of alpha, beta ethylenically unsaturated carboxylic acid unitssaid carboxylic acid units being about 5 to 95 percent neutralized.Optimal neutralization above 60 percent.

The level of the acid, the molecular weight, the percent neutralization,and the type of metal ion utilized will dictate the performance of theproduct, as well as, the compatibility. A higher acid and higherneutralized ionomer is essential for superior scratch resistance. Theaddition of a random copolymer of ethylene with ethylenicallyunsaturated carboxylic acid (acid copolymers) will not impartcompatibility or scratch resistance. Moreover, these higher flow acidcopolymers will impart surface tackiness and poor processability.

With the optional addition of a crosslinked portion, the compatibilitybetween the ionomer phase and the polypropylene phase appears to beimproved. This was particularly noted with the addition of a peroxide tothe rubber phase (i.e. ethylene and alpha-olefin copolymer; ethylene andalpha-olefin copolymers with unsaturated anhydride such as maleicanhydride.) This was seen both when completed in-situ and with therubber phase crosslinked prior to addition to the ionomer andpolypropylene.

Interestingly, work was completed using hydrosilylation of carbonylcontaining rubbers such as ethylene vinyl acetate with maleic anhydride,ethylene acrylate copolymers, and ethylene-polyolefin-metal salts(ionomers), and ethylene-polyolefin-metal salts with acrylate(ionomers.) Hydrosilylation crosslinking with platinum containingcatalysts offer other methods to crosslink the available carbonyl bondsrather than the traditional carbon-carbon double bonds of unsaturated,sterically unhindered rubbers/elastomers. This crosslinked rubber phasein combination with the ionomer and polypropylene offer some uniqueappearances, soft touch requirements, and physical properties withoutdeteriorating the scratch and mar resistance, heat cycle requirements ofpolypropylene, and or the low temperature impact performance.

In each of the aforementioned formulations, it may be advantageous toinclude one or more copolymers or interpolymers of styrene with graftedmaleic anhydride; a reaction product of ethylene vinyl acetate withmaleic anhydride or hydroxyl ethyl acrylate; a copolymer or terpolymerof ethylene, acrylate (glycidal methyl, methyl, butyl, or ethylacrylate), acrylic ester and or maleic anhydride; ethylene-propylenerubber with maleic anhydride; a low molecular weight ionomer wax orfunctionalized monomer.

In the above mentioned blend, there is the advantageous option toinclude: Styrenic block or random copolymers and or elastomers withmaleic anhydride grafting; ethylene and alpha-olefincopolymers/elastomers, potentially functionalized with maleic anhydride;ethylene vinyl acetate with maleic anhydride or hydroxyl ethyl acrylate;acrylate copolymers or terpolymers; terpolymers of ethylene, analpha-olefin, and a diene; and an ethylene propylene rubber with maleicanhydride grafting.

The copolymers of ethylene and alpha, beta ethylenically unsaturatedcarboxylic acid can be neutralized in situ with a metal salt or base.Examples of this would be sodium hydroxide or zinc acetate dihydrate.The percent neutralization would be a function of the molecular weightof the starting acid copolymer, percent acid (number of carboxylic acidunits), and the weight percent of the metal ion. For the best scratchand mar resistance, the optimal level of neutralization would be above30%, preferably above 60% with a starting acid content above 5 wt %.Examples of the suitable cations include, lithium, sodium, potassium,magnesium, calcium, cadmium, barium, lead, tin, zinc, aluminum or acombination thereof.

With sufficient vacuum and removal of volatiles such as acetic acid andwater from the neutralization, this reaction can be completed in situwhile crosslinking the rubber phase. The addition sequence of theingredients on an extruder is critical to the success of the blend.

The polyolefinic ionomer copolymer or terpolymer may include a P/X/Ycomposition where: P is the olefinic comonomer; X is an acrylatecomonomer, such as butyl, methyl or ethyl acrylate; and Y is thefunctional comonomer, acrylic and or methacrylic acid.

Ethylene ionomers may include the follow options, but are notexclusively limited to: ethylene/acrylic acid; ethylene/methacrylicacid; ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylicacid/iso-butyl acrylate; ethylene/acrylic acid/iso-butyl acrylate;ethylene/methacrylic acid/n-butyl methacrylate; ethylene/acrylicacid/methyl methacrylate; ethylene/acrylic acid/methyl acrylate;ethylene/methacrylic acid/methyl acrylate; ethylene/acrylic acid/b-butylmethacrylate; and combinations of such blends modified with one or moremetal salts.

Ionomer resins fall under the traditional trademarks of Iotek™ fromExxon Mobil; and Surlyn™ by E.I. Dupont de Nemours Co. The acidcopolymers would again come from Dow, Exxon Mobil, or Dupont. The lowmolecular weight ionomer waxes from Honeywell under the tradenameAclyn™.

The work completed within this invention, in contrast to the prior art,demonstrates that the compatibilization between the ionomer phase andthe propylene type polymer is dramatically improved with theincorporation of a functionalized and or crosslinked rubber/elastomer.For instance, the blends completed with the styrenic type blockcopolymers/elastomers when not functionalized with a hydrophilic moiety,ionomers, and polypropylene type polymers were dismissed. There wasinsufficient performance with regard to low temperature ductility, notchsensitivity, and low blushing. These materials appeared to significantlyimprove with the addition of maleic anhydride. Additionally, theperformance of the styrenic block copolymer/elastomer materials was notsuperior to other impact and interfacial modifiers when weighed againstthe cost criteria in a TPO and pure polypropylene application.

The copolymers of ethylene and unsaturated alpha-olefin, the acrylatecopolymers and terpolymers, as well as, the terpolymers of ethylene, andalpha-olefin and a diene may be crosslinked with peroxides or silanesprior to compounding with other constituent ingredients or in-situ.While the crosslinking agents assist with controlling the morphology ofthe blend and control the gloss level, it appears the peroxy groups maycontribute to some of the compatibility between the rubber phase,ionomer phase, and polypropylene domains. When completed in one step,the compatibility appears to improve within the respective blend. Theperoxide will partially crosslink the ionomer phase, and contribute tosome of the toughness and unique processability of this compound.Ionomers have thermally reversible, ionic crosslinking and notably havesuperior recovery after deformation. This recovery after deformationprovides the notable scratch and mar performance of these blends.

Styrene block copolymers are available from Shell Chemicals under theTradename, Kraton (inclusive of Kraton G™, Kraton FG 1901X™, Kraton FG1924X™,) Dexco Polymers with the Tradename Vector, and Septon grades ofSEP, SEPS, SEBS, SEEBS or Hybrar™ grades 5127, 5125, 7125 (Division ofKuraray.)

The invention further includes the option to incorporate acrylate typecopolymers and terpolymers such as, but not limited to: ethylene/ethylacrylate/maleic anhydride; ethylene/methyl acrylate/maleic anhydride;ethylene/acrylic ester/maleic anhydride; ethylene/butyl acrylate/maleicanhydride; glycidal/methacrylate/anhydride.

This portion may be added on its own or crosslinked with peroxide orsilane with a platinum catalyst. The silane and platininum catalyst maycrosslink the carbonyl portion of the polymer.

These acrylate type polymers are sold under the tradename of Lotader™from Atofina Chemicals.

The invention further includes the option to include terpolymers andcopolymer toughening agents such: as propylene, alpha-olefin and adiene, with or without maleic anhydride grafting; ethylene propylenerubber with maleic anhydride grafting and ethylene/alpha-olefinelastomers with maleic anhydride funtionality. These polymers may beutilized as is or crosslinked prior to use or in situ. Additionally,these compounds may be partially vulcanized thermoplastic elastomers.Suitable polymers are trademarked as: Vistalon™ from Exxon Mobil;Royalene™ from Crompton (Uniroyal Chemicals, a division of Crompton.);Nordel™ from DuPont Dow Elastomers; Santoprene™ from Advanced ElastomerSystems/Exxon Mobil; Fusabond MN 493 or Fusabond MN 416 from E.I. Dupontde Nemours Co Dupont.

The polyolefin blend in this invention may utilize the followingperoxides, but are not exclusively limited to: dialkyl peroxides suchas- dicumyl peroxide; a,a′ Di(t-butylperoxy)-diisopropylbenzene;2,5-dimethyl-2,5-Di-(t-butyl-peroxy) hexane;2,5-dimethyl-2,5-Di-(t-butyl-peroxy)hexyne-3; peroxy-ketal such as-n-butyl 4,4-Di(t-butylperoxy)valerate;1,1bis-(t-butylperoxy-)3,3,5-trimethyl-cyclohexane; diacyl such as:Dibenzoyl peroxide; peroxy-ester such as: t-butyl perbenzoate.

The polyolefin blend in this invention may utilize silane and platinumcatalysts.

This polyolefin blend contains stabilizers and chemical modifiers, whichwill improve the long term performance of the respective compounds andor enhance the aesthetics of the blends. These additives will notinterfere with the performance of the composition, most importantly thescratch and mar performance. Modifiers may include ultravioletabsorbers, hindered amine light stabilizers, secondary phosphites,antioxidants, and internal process aids, such as lubricants. These saidmaterials are trademarked under: Chimassorb™, Tinuvin™, Irganox™,Irgafos,™ P-EPQ™, Ultranox ™, Cyasorb™, and Ultranox™. These materialsare trademarked by Ciba Specialty Chemicals, Clariant Corporation, CytecIndustries, and General Electric Specialty Chemicals.

Another portion of the polyolefin blend may come from colorconcentrates; these would be added between 0 to 10 weight percent.

The polyolefin blend may further incorporate fatty acid type waxes orhigh molecular siloxanes or siloxane masterbatches to improve upon thescratch and mar resistance and cycling performance of these materials.These ingredients may be trademarked under Erucamide (ER, refinederucamide), Behanamide (BR, refined behanamide), Croda 203 (oleylpalmitamide) by Croda Universal; or trademarked as MB 50-001 (50% activein PP); MB 50-002 (50% active in PE); MB 50-321 (50% active in PP); MB50-008 (50% active in SAN.); MB 50-011 (50% active in nylon.) by DowChemicals.

These blends may include mineral and polymeric fillers to adjust thephysical properties of the blend. These may include, but not exclusivelylimited to talc, calcium carbonate, wollastonite, calcium sulfate,barium sulfate, metal fibers, nanocomposites, ceramic fibers andpowders, polymeric fibers, crosslinked polymers, mica, silica, carbonfibers, metal fibers, clay, glass fibers, glass spheres, conductivefillers such as polyaniline, and sulfonated materials such as AMPS.

EXAMPLES Example 1

In one embodiment the blend comprises: a polypropylene containingpolymer; a ethylene copolymer of functionalized elastomer, rubber,copolymer or terpolymer; this component may also be partially orcompletely crosslinked; and a polyolefin-metal salt of an ethylene-basedpolyolefin-metal salt that is a reaction product of an ethylene acidcopolymer with a metal salt ion. This neutralized ethylene-basedpolyolefin-metal salt must be neutralized at least 5% and should startwith an acid content above 5 weight %. The optimal performance is above60% neutralized with a starting acid content above 6wt %.

The polyolefin blend may contain between 10 to 80 weight percent ofpropylene polymers, homopolymer or a copolymer of propylene and ethylene(isotactic, atactic, syndiotactic polypropylene); from about 1 to 50weight percent of a functionalized elastomer, rubber, copolymer orterpolymer, and from about 5 to 60 weight percent of an ethylene-basedpolyolefin-metal salt that is a reaction product of an ethylene acidcopolymer with a metal salt. The percent functionality in the ethylenecopolymer should be between 0.5 to 35 weight %.

Example 2

The prior art described in U.S. Pat. No. 6,403,721 claims severalmethods for manufacturing a polypropylene modified ionomer blend. Theyclaim the following:

A method for manufacturing propylene-based polyolefin-metal saltsincludes the steps of contacting a propylene-containing polymer and anorganic monomer containing a hydrophilic moiety, and neutralizing thereaction product with metal ions.

A method for manufactuing ethylene-based polyolefin-metal salts includesthe steps of contacting a ethylene-containing polymer and an organicmonomer containing a hydrophilic moiety, and neutralizing the reactionproduct with metal ions. With the step of neutralizing thefunctionalized olefins with the metal ions at approximately the sametime as blending with the polyolefin. In this method, it is mentionedthat it is preferred to add an already functionalized propylenecontaining polymer as a separate component.

It also mentions an optional component being added as an interfacialmodifier. This is preferably a thermoplastic elastomer, including astyrenic block copolymer. This term references an elastomer having atleast one block segment of a styrene repeating unit in combination withsaturated and unsaturated rubber monomer segments. It is stated thatthis typically increases the toughness of the overall blend whilemaintaining rigidity. Furthermore, it is claimed that this interfacialcomponent is therefore an optional toughener.

It is to be understood that the invention is not to be limited to theexact details of operation, or to the exact compositions, methods,procedures, or embodiments shown and described, as obvious modificationsand equivalents will be apparent to one skilled in the art, and theinvention is therefore to be limited only by the full scope which can belegally accorded to the appended claims.

References Cited:

-   U.S. Pat. No. 4,888,391, December, 1989 Domine et al-   U.S. Pat. No. 6,207,761, March, 2001 Smith et al-   U.S. Pat. No. 6,403,721, June, 2002 Ding et al-   U.S. Pat. No. 6,169,145, January, 2001 Medsker et al    Other Publications

Article entitled “Dynamic Mechanical Properties of ThermoplasticElastomers from Blends of Polypropylene with Copolymers of Ethylene withVinyl Acetate” European Polymer Journal, vol. 28, pp. 1451-1458, Jan.29, 1992

1. A polyolefin blend comprising a propylene containing polymer, an ethylene copolymer elastomer, which is a reaction product of a copolymer of ethylene and at least one alpha-olefin, this elastomer functionalized with maleic anhydride, wherein the alpha-olefin is selected from 1-octene, 1-hexene, 1-heptene, 1-butene, 4-methyl-1-pentene, and mixtures thereof, and an ethylene-based polyolefin-metal salt which is the product of an ethylene acid copolymer and a metal salt, the polyolefin-metal salt being an ionomer, an alpha, beta ethylenically unsaturated carboxylic acid polymer in which the acid units are neutralized with metal ion (s).
 2. The polyolefin blend of claim 1, wherein the propylene polymer may be at least one of a homopolymer propylene or a random or block copolymer of propylene and ethylene, and the polyolefin blend may be from about 10 to 80 weight percent of the propylene polymer, from about 1 to 50 weight percent of the ethylene copolymer, and from about 5 to 60 weight percent of the polyolefin-metal salt.
 3. The polyolefin blend of claim 1, wherein the propylene polymer, for optimal hardness and scratch resistance, consists essentially of from 40 to 75 weight percent of the propylene polymer; from about 1 to 25 weight percent of the ethylene copolymer; and from 5 to 35 weight percent of the polyolefin-metal salt of the blend.
 4. The polyolefin blend of claim 1, wherein the ethylene copolymer is crosslinked with peroxide or silane with a catalyst selected from the transition metals of Group VIII, including complexes of these metals, this material optionally crosslinked prior to compounding or in situ.
 5. The polyolefin blend of claim 1, wherein the ethylene copolymer is a crosslinked/partially vulcanized thermoplastic elastomer.
 6. The polyolefin blend of claim 1, wherein the propylene polymer is selected from at least one of a homopolymer propylene, a random or block copolymer of propylene, and ethylene, and the polyolefin blend may be from about 5 to 75 weight percent of the propylene polymer, from about 1 to 50 weight percent of the ethylene copolymer, and from about 5 to 65 weight percent of the polyolefin-metal salt.
 7. The polyolefin blend of claim 1, which includes an interfacial impact modifier selected from a styrene-ethylene interpolymer, styrenic block copolymer or elastomer, and a random styrenic copolymer or elastomer, all of which may have been modified with maleic anhydride.
 8. The polyolefin blend of claim 1, wherein the styrenic copolymers, interpolymers or elastomers modified with maleic anhydride represent between 1 to about 30 weight percent of the blend.
 9. The polyolefin blend of claim 1, further comprising an ethylene vinyl acetate (EVA) with a vinyl acetate level between 5 to 80 weight percent with maleic anhydride or hydroxy ethyl acrylate.
 10. The polyolefin blend of claim 1, wherein the functionalized ethylene vinyl acetate represents between 1 to 30 weight percent of the blend.
 11. The polyolefin blend of claim 1, further comprising one or more of terpolymers or copolymers of ethylene, butyl acrylate, and glycidyl methacrylate (GMA); terpolymers of ethylene, ethyl, methyl or butyl acrylate, and maleic anhydride (MAH); terpolymers of ethylene, acrylic ester and maleic anhyrdride.
 12. The polyolefin blend of claim 1, wherein the MAH (unsaturated anhydride) and acrylate (GMA) may be physically crosslinked prior to addition to blend or in situ.
 13. The polyolefin blend of claim 1, wherein the modified acrylate copolymers or terpolymers may react with the free acid of the ionomer component.
 14. The polyolefin blend of claim 1, wherein the modified acrylate copolymer or terpolymers represent between 1 to 30 weight percent.
 15. The polyolefin blend of claim 1, wherein the polyolefin-metal salt is a copolymer or terpolymer ionomer, which is partially neutralized with a metal salt from 5 to 95%.
 16. The polyolefin blend of claim 1, wherein the terpolymer ionomer is modified with methyl, butyl, or ethyl acrylate; wherein the acrylate content from 1 to 25 weight percent.
 17. The polylefin blend of claim 16, wherein the acrylate content represents between 10 and 25 weight percent.
 18. The polyolefin blend of claim 1, wherein the metal ion is selected from the group consisting of lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum, cadmium, and mixtures thereof.
 19. the polyolefin blend of claim 1, wherein the ethylene copolymer may include a low molecular weight ionomer wax or functionalized monomer representing from about 1 to 20 weight percent.
 20. The polyolefin blend of claim 1, further comprising a filler from about 1 to 40 weight percent.
 21. The polyolefin blend of claim 1, wherein the mineral filler is selected from talc, calcium carbonate, wollastonite, calcium sulfate, barium sulfate, metal fibers, nanocomposites, ceramic fibers and powders, polymeric fibers, crosslinked polymers, mica, silica, carbon fibers, metal fibers, clay, glass fibers, glass spheres, conductive fillers such as polyaniline, and sulfonated materials such as AMPS.
 22. The polyolefin blend of claim 1, further comprising a surface and mold release agent such as high molecular weight silicone and silicone masterbatches, fatty acids (i.e. olyel palmitamide, erucamide and behanamide) representing from about 0.1 to 10 weight percent.
 23. A process for preparing an article from a polyolefin blend consisting essentially of: providing a propylene polymer containing polymer, adding a compound which may act as an impact modifier or interfacial agent selected from at least one of: ionomer waxes or functionalized monomers; impact modifiers and functionalized modifiers; a styrenic copolymer or elastomer with maleic anhydride grafting; ethylene vinyl acetate modified with maleic anhydride or hydroxyl ethyl acrylate; terpolymers or copolymers selected from one or more of ethylene, butyl acrylate, and glycidyl methacrylate; terpolymers of ethylene, ethyl, methyl or butyl acrylate, and maleic anhydride; ethylene-propylene rubber with maleic anhydride grafting, the ionomer portion may be a copolymer or terpolymer modified with acrylate; adding an ethylene based polyolefin-metal salt that is a reaction product of an ethylene containing polymer and a second organic monomer containing a hydrophilic moiety; such component being at least partially neutralized with a metal salt between 5 to 95%; mixing the ethylene copolymer until partially or completely crosslinked and adding to the blend; or crosslinking in situ while adding the propylene polymer and polyolefin-metal salt; or mixing the propylene polymer, ethylene copolymer, and polyolefin-metal salt; and injection molding, blow molding or extruding the blend into an article which will display high scratch resistance, low blushing upon impact, low temperature requirements when mandated, tape adhesion, molded in color, controlled gloss levels, superior weatherability, and sonic welding capabilities. 